In general, four requisites of the combustion for a combustion engine particularly, a boiler, which uses hydrocarbon fuel and fossil fuel, are air (oxygen), fuel, heat and a chimney. Among the requisites, the fuel is composed of an organic matter which is burned, and an inorganic matter (ash) which is not burned. However, in a case where the efficiency of combustion is increased by increasing a combustion speed of the organic matter to increase thermal efficiency, a high temperature of more than a melting point of the inorganic matter (the ash) is formed in the combustion engine, and thus the inorganic matter (the ash) is melted and is fused in the combustion engine, thereby causing heat loss by reducing heat transfer at the same time as obstructing driving of the combustion engine.
As a fuel system, which has been recently used in the combustion engine, there is a pulverized coal injection (PCI) system. The pulverized coal injection system enables combustion efficiency of the combustion engine to be improved by injecting a pulverized coal obtained by the cracking of a low-grade coal in an inner part of the combustion engine along with a heat wind in order to improve productivity per a unit capacity of the combustion engine and reduce a fuel price.
However, the pulverized coal injection system is disadvantageous that it would be difficult to normally drive the combustion engine because thermal efficiency and productivity of the combustion engine are reduced due to a sticking material generated from the ash melted in the combustion engine upon combustion using fossil fuel (coal and the like) which is a heat source.
Accordingly, it would be preferable to use a chemical method rather than a physical method in order to increase the efficiency of combustion in the combustion engine. Recently, an additive composition for increasing the efficiency of the combustion engine through a chemical reaction using an additive has been emerged as the chemical method.
In connection with this, to improve the efficiency of the combustion engine, a combustion promotion catalyst and an oxygen compound have been added to fuel used in the pulverized coal injection system, and thus a technology (i.e. Korean Laid-Open Patent Publication No. 10-2002-0075758) for improving the combustion efficiency and thermal efficiency of the combustion engine was developed. Also, as an alkali metal catalyst in which an alkali metal and a compound having oxygen are mixed has been used as a combustion promotion catalyst, a combustion reaction has been promoted, and an initial deformed temperature has been reduced, thereby inducing stable driving of the combustion engine and realizing high productivity.
However, the alkali metal as the conventional additive may function to promote combustion in the combustion state of a high temperature. However, it would be normally difficult to manage it at room temperature without a special device. Since an alkali oxide, which provides oxygen, is also unstable at room temperature, it would be difficult for it to exist in a liquid state. Thus, since the alkali oxide is used in a solid state and a non-ionic state, it is problematic that it would be difficult to show proper combustion efficiency. Accordingly, the additive composition in a liquid state having excellent stability and a strong ionic property has been urgently required.